1) Field of the Invention
The present invention relates to a specified image position estimating apparatus made to estimate a position of a specified image within an image, a specified image position estimating method, specified image position estimating program, specified position estimating program recorded computer-readable recording medium, and medium having an image to which a mark is affixed or added for estimating a position of a specified image.
2) Description of the Related Art
So far, a mark has been embedded in an image for estimating a position of a specified image in the image.
For example, Japanese Patent Laid-Open No. HEI 7-254037 discloses a technique in which a mark 30 (positioning symbol) having a square configuration shown in FIG. 18 is embedded in an image 31 to specify a position of a specified image (in this case, two-dimensional code) on the basis of this mark 30.
In addition, there has been proposed a technique in which, in a case in which a mark is affixed onto an image for some purpose, the mark is yellowed when the mark is placed in a white area on the image so that it becomes unremarkable (for example, see Japanese Patent Laid-Open No. HEI 9-018707).
Meanwhile, although Japanese Patent Laid-Open No. HEI 7-254037 employs a method of tracking, one by one, a pixel constituting an image as a method of detecting the mark 30 affixed to an image, this method cannot detect the mark 30 at a high speed.
Therefore, as a method of detecting a mark in an image fast and accurately, it is considered to scan a template having a shape similar to that of the mark in the image for detecting the mark on the basis of the agreement with this template.
However, in a case in which an image is picked up through the use of a camera or the like to fetch image data for detecting a mark in the fetched image, the size of the picked-up image and the size of the mark affixed to the image vary in accordance with the distance (imaging distance) between the camera and the image. In a case in which this mark has a shape shown in FIG. 18 or it is a triangular mark 33 shown in FIG. 19 in Japanese Patent Laid-Open No. HEI 9-018707, if the size of the mark varies as mentioned above, difficulty is encountered in detecting the mark through the use of the template having a fixed size, and difficulty is experienced in estimating the position of a specified image fast and accurately.